How Adiposity Ratio Works

The Adiposity Ratio Service is a clinical risk assessment that calculates your Waist-to-Height Ratio (WHtR) to determine your level of central (visceral) adiposity. Central adiposity is a key indicator of cardiometabolic risk, including risk of type 2 diabetes, cardiovascular disease, and metabolic syndrome.

The WHtR has been endorsed by NICE (National Institute for Health and Care Excellence) as a simple and effective screening tool for identifying individuals at increased cardiometabolic risk.

Yes. The Adiposity Ratio Service is classified as a class I medical device under UK MDR 2002 regulations, for its intended use.

You can view your Adiposity Ratio by navigating to the ‘Personalised Insights’ Section of the account homepage. Here you will see the Adiposity Ratio Service Card.

If you completed the ‘Health Profile’ information when you first created your NowPatient account, the score will automatically be calculated and appear within the Service Card. NowPatient uses the data in your health profile to automatically determine your risk.

If the ‘Health Profile’ was not completed, then you will see that the Adiposity Ratio Service Card is locked. Click the ‘Unlock’ button on the Service Card. This will present you with a series of questions which you will need to complete. Once you have completed the questions, you will be redirected to the account homepage, where you will be able to see your Score on the Adiposity Ratio Service Card.

The Adiposity Ratio Service uses the following data:

Date Used for Calculation:

• Waist circumference (cm or inches)
• Height (cm, metres, or feet/inches)

The Waist-to-Height Ratio is calculated using the following formula:

WHtR = Waist Circumference (cm) ÷ Height (cm)

Example: A patient with a waist circumference of 85 cm and height of 170 cm would have a WHtR of 0.50 (85 ÷ 170 = 0.50).

Measuring your waist circumference is important because it tells you about your central adiposity – the amount of fat stored around your middle. This type of fat, known as visceral fat, is stored around your internal organs and is more harmful to your health than fat stored elsewhere on your body, such as on your hips or thighs.

Research shows that central adiposity is a stronger predictor of serious health conditions than overall body weight or BMI alone. People with excess fat around their waist are at significantly higher risk of:

• Type 2 diabetes
• Heart disease and stroke
• High blood pressure
• Abnormal cholesterol levels
• Metabolic syndrome
• Sleep apnoea

The simple message from NICE is: “Keep your waist circumference to less than half your height.” By measuring your waist regularly, you can monitor whether your central fat levels are in a healthy range and take action if they are not.

Even if your overall weight or BMI appears normal, you may still have harmful levels of visceral fat. This is why waist measurement provides valuable information that weight alone cannot.

According to WHO guidance, waist circumference should be measured:

• At the midpoint between the lower margin of the last palpable rib and the top of the iliac crest
• With you standing, arms relaxed at sides
• At the end of a normal expiration (breathing out)
• Using a non-elastic measuring tape held snugly without compressing the skin

The Adiposity Ratio Service identifies and classifies your risk of obesity-related health conditions based on central adiposity. Central fat (visceral fat around your organs) carries greater health risks than fat stored elsewhere on the body. Our AI algorithms trigger warnings based on your risk factors.

If our algorithm identifies a risk, you will receive a push notification with clinical advice on what to do next, which will be sent to your device, as well as an In-App notification which can be viewed in your ‘Notifications’ Section of the account homepage.

You can also view the warning advisory by clicking the ‘View Warning’ button on the Adiposity Ratio Service Card.

If the Adiposity Ratio Service puts you ‘at increased risk’ or ‘very high risk’, it is very important that you speak to your doctor about screening for cardiometabolic risk factors.

NowPatient can also automatically qualify you for risk-reducing strategies such as the ‘Weight Loss Programs Service’. You will be notified if you are eligible for this.

Also, ask your doctor about programmes and services that could help reduce your central adiposity. These services will be different depending on where you live.

NowPatient provides a long-term trend graph that allows you to track your Adiposity Ratio over time. This easy-to-use feature helps you visualise your progress and see the impact of lifestyle changes and interventions.

Here’s how the tracking system works:

• Monthly reminders: You will receive a push notification and in-app reminder once a month, prompting you to update your waist measurement. This helps ensure your data stays current.
• Long-term trend graph: All your measurements are displayed on an interactive graph that shows your WHtR history over time. The graph uses colour-coded zones (green, amber, red) so you can easily see which risk category you fall into.
• Progress tracking: The graph shows your trend direction – whether your WHtR is improving, stable, or worsening – so you can see the results of your efforts.
• Quick updates: Since your height doesn’t change, you only need to enter your new waist measurement each month. It takes just seconds to update.

To view your trend graph, tap on the Adiposity Ratio Service Card and select ‘View Trend’ or ‘View History’. You can zoom in on specific time periods or view your complete measurement history.

Regular tracking is important because it allows you to:

• Monitor the effectiveness of diet and exercise changes
• See the impact of any weight loss medications
• Stay motivated by viewing your progress
• Share accurate, up-to-date information with your healthcare providers
• Catch any concerning trends early before they become serious

We recommend measuring your waist at the same time of day each month (such as first thing in the morning) for the most consistent results.

NowPatient uses the Waist-to-Height Ratio (WHtR) method to evaluate your central adiposity risk.

A boundary value of WHtR 0.5 as a risk assessment tool was first suggested in 1996 by Ashwell and Cole, and has been validated across numerous global populations. The message ‘keep your waist circumference to less than half your height’ is now recommended by NICE (October 2022) as a simple and effective public health message.

A key advantage of WHtR is that the same threshold values apply across all adult ages, both sexes, and all ethnic groups – avoiding the need for age, sex, and ethnic-specific boundary values.

We advise all users to update the ‘Health Profile’ monthly and also before any NowPatient Service Consultations that you may book.

You will receive a monthly reminder prompting you to update your waist measurement. Simply tap the notification to go directly to the measurement input screen, enter your current waist circumference, and your Adiposity Ratio will be recalculated automatically.

The updated information you submit to the ‘Health Profile’ may affect your Adiposity Ratio. This will be reflected in the Adiposity Ratio Service Card as an updated score and added to your long-term trend graph. This allows you to track the benefits of any lifestyle or medication interventions.

The WHtR boundary value of 0.5 for increased health risk was first proposed by Dr Margaret Ashwell and Professor Tim Cole in 1996. Since then, it has been validated in numerous studies across diverse global populations and has been adopted by NICE in their October 2022 guidelines as a recommended screening tool for central adiposity.

The scores only indicate the likelihood of obesity-related health risks. It does not mean you will definitely develop these conditions. Early risk-based interventions and lifestyle changes – such as improving diet, increasing physical activity, and achieving weight loss – can significantly reduce your risks.

The Adiposity Ratio calculation utilises the Waist-to-Height Ratio (WHtR), which is a widely used and validated tool to assess central adiposity risk.

As with any risk assessment screening, there are limitations:

• Not standalone: Should be used with other clinical assessments
• Abdominal conditions: Results affected by ascites, pregnancy, or other causes of abdominal distension
• Height extremes: Very short or tall individuals may require additional clinical judgement
• Fat type: Does not distinguish between subcutaneous and visceral fat
• BMI range: NICE recommends using WHtR for patients with BMI under 35 kg/m²
• Self-report errors: Users may misreport waist or height measurements

Elevated WHtR (≥0.5) is associated with increased risk of the following conditions:

• Type 2 Diabetes Mellitus
• Cardiovascular Disease (coronary heart disease, stroke)
• Hypertension (high blood pressure)
• Dyslipidaemia (abnormal cholesterol levels)
• Metabolic Syndrome
• Non-Alcoholic Fatty Liver Disease
• Obstructive Sleep Apnoea
• Increased all-cause mortality (for WHtR ≥0.6)

Signs and symptoms that may indicate obesity-related health problems include:

• Increased thirst and frequent urination
• Fatigue and feeling more tired than usual
• Shortness of breath during normal activities
• Snoring or interrupted breathing during sleep
• Joint pain, particularly in weight-bearing joints
• Skin changes, including dark patches (acanthosis nigricans)
• Difficulty with wound healing
• High blood pressure readings